3D printing for artificial blood vessels

In Pay the Printer, Philip K Dick imagined a species called “Printers” who could organically create perfect copies of complex objects. In this world, the increasingly-popular 3D printer can’t create a car, but its ability to produce simple 3D objects is being used to create blood vessels.

The researchers, led by Fraunhofer’s Dr Günter Tovar, have combined 3D printing with multiphoton polymerization to create an artificial blood vessel, which they will be demonstrating at the Hannover Biotechnica Fair in October.

A 3D printer can’t build things on a small enough scale to create a structure as small as a blood vessel, so instead, it is used to lay down a substrate that the blood vessel will be created in.

In multiphoton polymerization, the creation of polymers in the target material is triggered by a focused laser. This allows the formation of polymer chains to be controlled at the nano scale.

By combining the two, the researchers have found that they can create the target material very quickly, using the laser to create the artificial blood vessel.

The other key development is in the materials used: you need a material that can be turned into a polymer, but that can also be bonded to living tissue. Merely creating a small, plastic tube the same size and shape as a blood vessel isn’t enough.

The 3D printer is loaded with inks that contain both synthetic polymers and the modified biological molecules, including heparin (a useful anti-coagulant) and anchor peptides. The finished vessels also have to include endothelial cells, and they have to mimic natural blood vessels well enough that natural cells can attach to the vessels, and nutrients can pass through them.

The technology is at its earliest stages, but Dr Tovar believes the artificial vessels could one day be used in applications like bypass surgery. More here. ®